How can I check for collision against all components of the same class?

Question

I have a small school project, of which I am required to create a simple game (platformer). I have been messing around with this which I found:

Var
 Overlay : Trect;
Begin
 If not intersectrect(Overlay, player.boundsrect, shape1.boundsrect) then
  //code
end;

This checks if the Player is colliding with shape1 and prevents falling past the shape. My problem is that I am creating the shapes at run time in an array. I can't check for collision against each shape, especially if there are many and could be problematic checking multiple times every timer tick.

Can I somehow do something like this:

If not intersectrect(Overlay, player.boundsrect, arrayShapes[1..20]);

or create an event that only triggers when player collides with a component, then checks if that component is a shape?

If not, is there a better way to accomplish this without checking against each shape?

Possible duplicate of [Delphi custom animation - collision detection](http://stackoverflow.com/questions/15308077/delphi-custom-animation-collision-detection) — Jerry Dodge, Feb 07 '17 at 17:48
Animation using controls for sprites is a performance nightmare. Expect pain. — David Heffernan, Feb 07 '17 at 19:16

MBo · Accepted Answer · 2017-02-07T17:48:12.643

1

Rectangle intersection is very simple function and there no problem to check some hundreds/thousands of intersections.

for i := Low(arrayShapes) to High(arrayShapes) do
  if IntersectRect(Overlay, player.boundsrect, arrayShapes[i]) then
      DoSomething

If you want more effective approach, consider using some spatial indexing structure like R-tree. It allows to determine what rectangles are touched by given object without brute-force

edited Feb 07 '17 at 17:48

answered Feb 07 '17 at 17:32

MBo

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Alright thanks for clearing that up, How can I check all the shapes existing in the whole array? – User09871 Feb 07 '17 at 17:36
You could use a loop, @User. – Rob Kennedy Feb 07 '17 at 17:38

How can I check for collision against all components of the same class?

1 Answers1